Assighstoe of two-thieds to julius



r-W it" we 6. COMPOSITION COATING OR PLASTIC.

pee-w STATE I ALFRED L-ILLEY, on FREMONT; 01110,

o v|i=os|T|oN Fo -BLAcKBoARos,

PATENT OFFICE.

ASSIGNOB F Two-ramps TO JULIUS .LlIIEHLE ANDXGHARLES PARDOE, BOTH OFSAME PLACE.

s EcIHcA'rI'on-rormm part of Letters Patent 1303513 29, dated Qctqber19,1886.

' Application filed March 2, 1886. Serial No. 193,810,. (No specimens.)

To all whom it may concern: I

Be it knownthat I, ALFRED LILLEY, a citi-' zen of the United States ofAmerica, residing at Fremont, in the county of Sandusky and 5 State ofOhio, have invented certain new and useful Improvements inCompositionfor Blackboards, of which the following is a specification. e I

My invention consists in an improved comro pound for constructingschoolblackboards,

' substantially as hereinafter more fully described. v

In the preparation of my compound I take sixty parts pf Portland cementone part of 1 lam black or lVOl -BIa'cE or lts equivalent,

an i r r i m id the latter being known to mo ers as 1% send whi h h y poy eenarateczs- 2o flasks. Itis ordinarily procured by sept rating fromcastings the burned sand adhering to them, and one part of powderedemery'.

- mggeneouscompgund. Theparting-sand having its color burned into itdoes not fade-nor become inthe least less black than whcniirst made, andit gives a fine gritty surface,yvhich \I is peculiarly adapted forcausing the chalk to V mark-distinctly, the Portland cement renderv ingit hard and-durable. I r V r The compound thus made is spread and formedinto blackboards by any ordinary means. a I am aware that it is not newto construct a blackboard of, first, hydraulic cemen t sand, calcinedsulphate of lime, and lime; and, sec ondly, of hydraulic cement,calcined sulphate of lime, black sand, and lamp-black; but I'do 0 notmake any claim to such composition ofingredients. 1

Having thus fully described my -invention, what I claim, and desire tosecure by Letters Patent, is 5 The herein-describedblackboard'composition,consistingofPorment 1am black or ivor -blac lz,parting-sand, and pow e emery, in about the proportions specified, and

- for the purpose stated. I The lam black or ivor -bla k is first cut:"'-with" aI'cohoI and then the ingredients. are

2 5 thorougHIy lnterm-ixed and blende llinto a g

